TS 155 
.F48 
vol. 9 

no. 2 
Copy 1 


HOW TO SOLVE 
OUNDRY PROBLEMS 

* 

BY 

DR. RICHARD MODDENKE 

LECTURE No. 34 

OF THE 

FACTORY MANAGEMENT 
COURSE AND SERVICE 



Volume 9, Lecture 2 


INDUSTRIAL EXTENSION INSTITUTE 

INCORPORATED 

NEW YORK 

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HOW TO SOLVE 
FOUNDRY PROBLEMS 


BY unKA 

DR. RICHARD MOLDENKE 

Ik 


LECTURE No. 34 

OF THE 


FACTORY MANAGEMENT 
COURSE AND SERVICE 



Volume 9, Lecture 2 


INDUSTRIAL EXTENSION INSTITUTE 

INCORPORATED 

NEW YORK 



Dr. Moldenke graduated from the School of Mines, 
Columbia University in 1885 as Engineer of Mines, 
receiving the degree of Doctor of Philosophy from the 
same university in 1887. In later years he served as 
Professor of Mechanical Engineering, Michigan Mining 
School; in the United States Coast & Geodetic Survey; 
as member President Roosevelt’s Advisory Board for 
Geological Survey; as Foundry Expert for Bureau of 
Mines; as Vice President to one of New Jersey’s State 
Boards, and as Director in many mining and industrial 
corporations. He has also served as consulting metal¬ 
lurgist specializing in Cast and Malleable Iron, and has 
been connected with many large manufacturing estab¬ 
lishments operating foundries in a consulting capacity. 
Dr. Moldenke is a member of Amer. Inst. Mining & Met. 
Engineers; Amer. Soc. Mechanical Engineers; British 
Iron & Steel Inst.; Amer. Soc. Testing Materials; Amer. 
Electroehem. Soc.: an honorary member Amer. Foundry- 
men ’s Association, British Foundrymen’s Asso., and 
foundrymen’s associations of New England, Pittsburgh 
and Newark. He is the author of many papers on 
foundry practice, a book on “Production of Malleable 
Castings” and a later book on “Principles of Iron 
Founding.” 


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JUL 12 1922 

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HOW TO SOLVE FOUNDRY PROBLEMS 


Bv Dr. Richard Moldenke 


Importance of Good Management.—Few situations 
in industrial management involve such a mass and 
variety of detail based upon sound knowledge as the 
operation of a foundry. To be a successful manager, 
independent of trained assistants if need be at a 
pinch, considerable reading and study is essential to 
master enough of the elements of mechanical en¬ 
gineering and metallurgy to serve. This apart from 
the general study of economics and scientific manage¬ 
ment, and all of it is necessary in order to under¬ 
stand and direct every department of the complicated 
industrial fabric called the foundry. Not only must 
every wheel of what may be a huge industrial ma¬ 
chine function correctly in the conversion of piles of 
pig iron and scrap into servicable castings, but these 
piles of raw material must be bought with foresight 
and economy and the castings utilized or sold to best 
advantage. With favorable location and markets the 
successful foundry manager can build up a wonder¬ 
ful industry in a community, and be an important 
personality therein. 

Considerd from the managerial standpoint, there 
will be two kinds of foundry development to study; 

Copyright, 1921, The Industrial Extension Institute. Inc.. New York. 


3 





4 


FOUNDRY PROBLEMS 


namely, the foundry forming part of an industrial 
enterprise, and the independent jobbing foundry. In 
each case, the foundry may consist of one or more 
divisions of the art, such as the making of gray iron, 
steel, malleable, brass and bronze, and aluminum cast¬ 
ings. Each class of work has its own peculiarities, 
characteristics and requirements, but they are all 
amenable to the same line of operative attention from 
the managerial standpoint, and what follows applies 
equally to gray iron castings as to the others. 

The usual development of a foundry forming part 
of an industrial enterprise came from a jobbing shop 
which branched out into a specialty. Less frequently 
a manufacturing plant would grow tired of the delays 
and troubles with purchased castings and find it 
cheaper to go into the making of castings, particu¬ 
larly where big tonnages were involved. The ulti¬ 
mate trend of all foundries, however, means that the 
great majority of large foundries are becoming parts 
of equally large manufacturing establishments, and a 
large jobbing foundry doing no machine finishing is 
rather the exception today, though there exist many 
small jobbing foundries that hope some day to spe¬ 
cialize in some direction. 

Location and Arrangement.—The question of loca¬ 
tion and plant arrangement or of re-arrangement will 
constantly be in the mind of the manager, for an 
establishment not going through a continual process 
of evolution stands still or soon falls behind. Every 
manufacturer tells you that he hopes some day to be 
really turning out perfect product from a finished 
plant, but that day never comes to the man in the 


FOUNDRY PROBLEMS 


5 


front line of his division of the industrial procession. 
Questions of removing a plant bodily to a more 
favored locality do not come up very often, but a re¬ 
arrangement of the operating units and improvement 
in manufacturing facilities should always be under 
consideration. The nature of the work may allow a 
routing of raw material to finished product which 
suggests a top-floor foundry with adequate economic 
raw material hoists, and a succession of downward 
movement of the product in its several manufactured 
stages to the distribution point of the finished work 
on the ground floor. This is particularly the case in 
large cities with such castings as soil pipe and fit¬ 
tings, hardware, and where many items must be 
stocked and distributed in variety and in small lots. 

The important fact to be remembered by the execu¬ 
tive head of a manufacturing enterprise is that the 
arrangement of a foundry usually considered essen¬ 
tial should not be a deterrent in planning out the 
most economic system of operating the plant as a 
whole. Many things can be done with a foundry that 
appear inadvisable at first glance, but which on closer 
study can be worked out successfully and harmoniz¬ 
ing with the general plan in view. The foundry need 
not necessarily be a stubborn fact which must be 
handled either one way or not at all. If the general 
scheme calls for a foundry on the sixth floor, put it 
there and work out the necessary details of operation 
that will ensue. If the plan calls for continuous 
operation, arrange the labor end to suit the conditions, 
for persistency in this will win out in spite of ap¬ 
parently unsurmountable difficulties. If large instal- 


6 


FOUNDRY PROBLEMS 


lations of labor-saving machinery prove advisable, 
put them in, but do not make the common mistake 
of expecting results without brains to operate them 
efficiently. Make the foundry factors fit your plan if 
this is based on correct principles, rather than make 
your plan to fit the foundry factors. One does not 
realize how readily foundry factors—such as mold¬ 
ing, melting and finishing processes—yield to intel¬ 
ligent and advanced ideas of arrangement and opera¬ 
tion until one tries. This is real empire building by 
advanced thinkers in the industrial field. 

Fundamentals of Successful Practice: Material.— 
Before taking up the discussion of problems in foun¬ 
dry routine, it is well to point out the three funda¬ 
mental requirements of successful foundry practice. 
These are: first, the necessity of stocking up with 
good raw materials. Only well made pig irons are 
desirable; “off” irons usually mean trouble, except 
when used for special purposes. Similarly the scrap 
bought should be free from “burnt” material. Good 
ingot copper, brass or aluminum and corresponding 
scrap should be used, the only allowable situation for 
inferior material for making the ferrous castings 
being where a basic-hearth electric furnace refines 
the metal previous to pouring. The best of coke, 
molding sands, and the usual supplies for finishing 
molds and making cores are only good enough, for it 
is idle to expect good castings from poor material. 

2. Melting.—The second fundamental requirement 
of successful foundry practice is to use high class 
methods of converting the good raw materials above 
mentioned into the right kind of molten metal or 



FOUNDRY PROBLEMS 


alloys to be poured into properly made molds. The 
proper melting method should be selected and carried 
through with the least degree of oxidation possible. 
The molten metal or alloy should have the proper 
temperature, be right in composition, in shape for 
effective pouring, be properly skimmed, and go into 
molds which are as nearly perfect as the art of the 
molder can make them, the mold surfaces being 
properly finished off to yield good surfaces on the 
castings. Good material charged into the furnaces 
can be spoiled in the melting, hence the best of atten¬ 
tion is required here. 

3. Adequate Gating.—The third fundamental re¬ 
quirement is that the good materials, well melted and 
going into good molds, should be given the best })os- 
sible chance to feed up properly, so that as nearly a 
sound casting may result as is possible in practice. 
This means good judgment in gating the molds. This 
subject alone is one for a life study, and many a 
veteran foundryman falls down when getting the 
mold for a new job ready for pouring. Unless the 
molten metal can be made to reach the end point of 
its travel direct and quickly, and remain there to set, 
it will not feed itself from the fresh metal behind it, 
gradually setting until the entrance gate is reached. 
The result will be liquid portions of metal imprisoned 
within walls of metal already set, and then the \ ol- 
ume contraction incident to the conversion of liquid 
to solid metal takes place—with a bad “shrink” as 
the result. The subject of gating is therefore a most 
important one, for unless good metal, well melted, is 
given its best chance through the medium of proper 


8 


FOUNDRY PROBLEMS 


gates in the mold, the easting will not be reliable. 
These three points form the sum and substance of 
successful foundry procedure, and should be con¬ 
stantly kept in mind by the manager in locating the 
source of defective work. The relation of these points 
to the subjects of metallurgy and mechanical en¬ 
gineering are obvious, and emphasize the desirability 
of the manager to be well posted on them. 

Yard Facilities.—A foundry is built for the conver- 
sion of suitable raw materials into saleable castings. 
The plant arrangement must, therefore, necessarily 
hinge upon the economical transit of the materials 
used in the various stages of their manufacture. Pig 
iron, scrap, coke, molding sand, etc., must converge 
from the respective places of storage to common 
points of assembly, so that they may perform their 
respective functions. This means, in the first place, 
ample and well arranged yard facilities for receiving 
and storage of the raw materials received by rail or 
water. Similarly, for the non-ferrous and more ex¬ 
pensive metals, warehouse facilities with direct rail¬ 
road siding connection are essential in medium to 
large shops. Pig iron and scrap are piled as com¬ 
pactly and conveniently as possible, and carefully 
marked for identification. The gantry crane and 
magnet for unloading and transfer of iron are now 

universallv used where room is available. And there 
«/ 

should be such room for yard storage purposes, for 
many times castings have been lost from a mix-up in 
irons due to insufficient storage space in a yard 
cramped by building extension. 

Sand Storage.—Sand sheds, coke supplies under 



FOUNDRY PROBLEMS 


D 


cover, open bins for scrap where much of this is used, 
and industrial trackage for economical distribution 
where required mean but little in first cost, but cut 
down labor astonishingly. Where the foundry sand 
problem can be solved by storing it in a suitable base¬ 
ment under the foundry floor, where it will be free 
from frost and can be prepared for next day’s work 
ready to be conveyed to the floors above, greater effi¬ 
ciency will result, costs will be lower, and the sand 
will be delivered to the floors in better condition for 
the molder. 

The subject of molding sand is in itself an intri¬ 
cate one, for not onlv is it necessary to select a first- 
class sand, but also to keep it in good bonding and 
venting condition. With all the sand from the molds 
as shaken out—after the removal of the work—going 
through a rejuvenating process by the addition of 
new sand, and the “tempering” with water done at 
one point instead of all over the foundry floor, the 
resulting material is bound to be more uniform, the 
water better disseminated and strict attention to the 
bond and other qualities possible. 

Scientific Cupola Charging. — Handling material 

costs monev everv time it is touched. Hence the 
•/ */ 

several devices for charging the cupola mechanically. 
While all of these are suitable from the mechanical 
standpoint, the author believes that from the metal¬ 
lurgical side the only correct method of charging 
mechanically is where the equivalent of hand-charg¬ 
ing is accomplished by mechanical devices. This 
means a straight drop of the pig, scrap, and coke, so 
that the layering is exactly as it would be if charged 




10 


FOUNDRY PROBLEMS 


by hand. Side-charging of the cupola is fundamen¬ 
tally wrong and is the cause of many lost castings 
from pin holes and shrinkage, for it is impossible to 
maintain a level bed and oxidation of the iron must 
result. Managers of large foundries should, therefore, 
use some form of charging device operated on the 
above principle, first advocated by the writer, which 
means the use of bottom-drop buckets charged in the 
yard, brought up and into the cupola, emptied and 
returned again — the pig, scrap, and coke being- 
touched but once from yard to melting. 

Labor Saving in Handling Material.—Among the 
more recent aids to economical handling of materials 
in the foundry there may be mentioned the grab- 
bucket operated by the regular foundry traveling- 
crane, with which molding sand may be taken about 
the floors quickly, cheaply, and in quantity. Then, 
the small elevating conveyors operated by motor, that 
may be placed between a sand-lieap and a large flask 
which is to be rammed up, whereby shoveling be¬ 
comes easier and time is saved. Again, the adapta¬ 
tions of the small 44 tank” for both yard and foundry 
transportation; these little tractors pay for them¬ 
selves rapidly and haul astonishing loads. It is thus 
possible to handle the transportation problem in the 
foundry very economically these days, and the super¬ 
intendents should see that foremen are fully alive 
to the opportunities for saving manual labor at every 
point. 

The Melting Process.—With materials for melting- 
brought to the cupola or air furnace for the gray iron 
and malleable foundry, to the open hearth for steel, 



FOUNDRY PROBLEMS 


11 


to the various forms of crucibles for the non-ferrous 
metals and allovs—or to the electric furnace for all 
of them—the melting process should come next. It 
should be said here that managers should keep their 
eyes upon the progress made with the electric fur¬ 
nace. It is rapidly replacing other melting processes 
for the non-ferrous metals and alloys, has long been 
used for making steel castings, and is just coming 
into the malleable and gray iron foundry. The basic- 
hearth furnace offers the best possibilities for iron 
and steel castings, for there are three accomplish¬ 
ments to be taken advantage of: first, the tremendous 
super-heat obtained; next, the consequent deoxidation 
possible in the case of cast iron where the large car¬ 
bon percentages make this effective when conditions 
are kept right, and last, an effective desulphurization 
depending upon the time allowed. The electric furnace 
may either do the melting from cold stock or from 
“duplex’’ molten metal taken from the cupola. The 
latter method is advisable as it is cheaper and only 
part of the cupola run need be taken for refinement 
in the electric furnace, for the special jobs, the bal¬ 
ance going into regular work. The refining action of 
the furnace makes it possible to use lower grade stock 
for the melts, and hence the extra cost of the process 
is balanced by the cheaper mixtures. 

Whatever melting process is used in a foundry par¬ 
ticular care should be exercised to see that it is 
carried out as perfect in detail as can be, for here is 
where nine out of ten cases of trouble have their 
origin. All melting processes are to a greater or less 
extent of an oxidizing nature. One has but to scan 




12 


FOUNDRY PROBLEMS 


the analyses of mixtures before and after melting to 
observe this. The crucible melting process shows 
this least and the open hearth furnace most. Mix¬ 
tures are, therefore, always calculated with this oxi¬ 
dation in view, so that the molten metal—with the 
resulting castings—may come out with proper com¬ 
position. 

Intelligent Supervision on Charging Platform.— 

There are two places in a foundry where it will pay 
to put young men of promise. One is on the cupola 
platform in charge of operations there. Whatever 
melting process is used, the materials going in as 
mixtures consist of new stock, such as pig iron, 
copper, zinc, aluminum, etc. remelted material, 
called “home” or domestic scrap — consisting of 
sprues, the gates, risers, lost castings and “over¬ 
iron” of a melt—and purchased or “foreign” scrap. 
It is important that the quantities required to give 
an average predetermined composition should be cor¬ 
rectly weighed and actually get into the cupola. This 
is also true in the case of brass or bronze when melt¬ 
ing in the usual crucible furnaces, or latterly in the 
electric furnace. Furthermore, fuel, if charged with 
the metal, must also be provided in accurate quantity, 
so that the melting process may function properly 
and yield the expected results. Hence the necessity 
of intelligent supervision at this critical point. Where 
ordinary labor is entrusted with the weighing and 
charging operations, an occasional coke charge is 
either forgotten or doubled, and many a time the 
wrong kind of pig iron is taken from the yard. Under 
such circumstances why wonder at poor castings? 


FOUNDRY PROBLEMS 


13 


In most furnace melting operations it is possible 
to promote uniformity in metal composition and tem¬ 
perature by frequent rabbling of the bath after the 
charge has melted down. This is not the case with 
the cupola, where a considerable part of the day’s 
run is charged before any molten metal is obtained. 
Corrections are not possible, and hence extreme care 
is necessary that the individual charges of metal and 
intermediate coke go in level and uniformly dis¬ 
tributed over the area, and that quantities and pro¬ 
portions fit the metallurgical requirements of the 
melting process. 

In the case where the cupola is employed it is essen¬ 
tial that the bed upon which the actual melting is 
done has the proper height to insure the complete 
utilization of the oxygen of the blast; that in melting 
the successive charges this bed is not lowered more 
than about four inches at a time, the replacement by 
the intermediate coke charges being such that the bed 
is brought up just right again every time; that this 
situation is maintained throughout the heat from 
4 ‘blast on” to “drop bottom”. With a proper coke 
ratio, small charges, constant volume blast of proper 
relation to the cupola capacity, the molten metal 
should come out white hot and full of “life”—as the 
foundryman calls it—or “unoxidized,” as the metal¬ 
lurgist would put it. Such metal, if the melting stock 
was of good quality and the gates are cut scientifi¬ 
cally, will turn out any casting successfully, and 
should be striven for by the manager as the touch¬ 
stone upon which he retains and advances his super¬ 
intendents and foremen. 



14 


FOUNDRY PROBLEMS 


Intelligent Supervision in Sorting Room. —The 

other important place in the foundry tits closely with 
the above situation; that is, in the sorting room 
where the bad work is culled out. With bad mater¬ 
ials, bad melting, bad gating, singly or in combina¬ 
tion, the percentage of defective work rises rapidly. 
In fact it increases day by day, for the sprues carry 
an increment of oxidation or other evils from one 
heat into the next and therefore operate cumulatively. 
Hence, from a normal of say four per cent of lost 
work before the machine shop is reached, the figure 
may soon run up to thirty per cent or more. The 
man in charge of the sorting room, the man who has 
the scrapping of bad work must catch the defects 
before they become serious and urge prompt atten¬ 
tion upon his superior. He should be able to dis¬ 
tinguish between losses due to molding sand troubles, 
to bad molding, to cores, or to dull, oxidized, hard 
iron, etc., and keep a daily record of distribution of 
losses. In that way the daily sheet quickly shows up 
a black spot composed of individual marks against 
some special defect. Calling attention to the respon¬ 
sible man to see this is corrected puts the onus on 
him to make good, and to do this quickly, otherwise 
the whole shop and the management itself soon wants 
to know why. Of what avail is it to turn out molds 
by the hundred only to lose a heavy percentage of 
them. Quality work is always cheaper than quantity, 
within reason. The man sorting out bad work has in 
his hand the reputation of the establishment, and 
hence should be a man of parts and not afraid to do 
his duty. 


FOUNDRY PROBLEMS 


15 


Good and Bad Features of Machine Molding, —The 

introduction of the molding machine into foundries 
lias constituted a great forward stride in the replace¬ 
ment of manual labor by mechanical operation. If 
for no other advantage than this, the change is to be 
welcomed—for coal is cheaper than muscle. How¬ 
ever, just as labor fought the steam engine originally, 
so it is today still fighting the molding machine by 
every means possible, no matter what protestations 
are made to the contrary; and managers must not be 
disconcerted in extending the use of machine molding 
wherever it proves an advantage by the open or un¬ 
derhand opposition of the molding fraternity. The 
work moves on, and whoever opposes its progress 
eventually gets under the wheels. 

With all the advantages of the molding machine in 
its proper place, two bad features are still outstand¬ 
ing. One is that the operative becomes a human ma¬ 
chine, simply registering the several movements auto¬ 
matically, his mind little occupied and intent only on 
turning out molds in sufficient quantity to get good 
pay without killing his job. The other objection is 
that while the molding machine itself is now a very 
perfect mechanism, the means for removing the fin¬ 
ished work from the platen and placing the molds on 

the floor is an almost untouched problem. The efficient 

• 

operative of today may have to carry five times the 
number of molds, and over a wider floor space than 
was the case with hand-molding. This takes a strong 
back and means that the manual labor applied during 
the working day is hardly less than formerly, while 
the production has been increased tremendously. The 



16 


FOUNDRY PROBLEMS 


problem of carrying the metal can be solved by the 
organization of a pouring gang, but the actual han¬ 
dling of the finished mold on the floor still remains. 
Only in a few establishments has this problem been 
solved by the use of moving platforms and mold con¬ 
veying systems. The field is still open for inventive 
genius for the great majority of foundries that oper¬ 
ate today. 

Danger of Losing Skilled Men. —With the multipli¬ 
cation of molding machines there is a further danger 
of deterioration in the number and quality of molders. 
The present tendency is to break in new men on 
machines, who when satisfactory are allowed to re¬ 
main on the several jobs day in and day out. The 
average foundry superintendent — formerly called 

foreman—hates to take a man awav from a machine 

•/ 

on which he is doing well, in order to put him on 
other kinds of work so that he may perfect himself 
and become an asset to the shop and himself. And 
yet this very thing must be done if the art of molding 
is to live. Modern practice is to replace loam-mold¬ 
ing by dry-sand work as much as possible. With the 
jarring machine and its increasingly understood pos¬ 
sibilities, the matter of large cores has also come to 
the front. Hence the elimination of much of the 
talent formerly required for successful foundry oper- 
tion. 

This is all good so far as it goes; for the installa¬ 
tion of huge drying ovens, modern core-making ap¬ 
pliances and shop rigging planned on a large scale, 
is obviating much of the skill that was formerly 
essential. None the less, there should be a fair per- 



FOUNDRY PROBLEMS 


17 


centage of skilled men in the shop, and these must he 
trained by the general foundry trade and not in a 
few shops only. Hence, the far-seeing manager should 
encourage the trade school, continuation school, pub¬ 
lic lectures and any form of education which will 
make men think. The remuneration for skilled work 
is now so high that the more sheer drudgery is taken 
from shop routine, and the more a man may use his 
brain for refinements in bringing out physically per¬ 
fect molds, the better the class of men attracted and 
held. Hence molders and helpers should be given the 
chance to learn all classes of molding operations. 
Those who remain impervious to progress will re¬ 
main functionaries the rest of their lives; the few 
that have it in them move up in responsibility and 
emolument. 

Improvements Effected in Patterns. —Without go¬ 
ing into the very special subject of molding machines, 
one very beneficial effect is felt in every progressive 
shop. The improvement of patterns and pattern 
equipment is most noticeable everywhere, particularly 
in the specialty shops. The pattern shop of today is 
a vastly different place than was formerly the case. 
With the constantly increasing use of metal patterns, 
and the rigging up for molding machines, the pat¬ 
ternmaker of today is indeed a highly skilled man, 
and the investment in his branch of the foundry is a 
heavy item. The simpler the methods oi plating pat¬ 
terns, the greater the number of castings that can be 
made on a machine economically. The greater the 
variety of machines in a shop, rather than their num¬ 
ber, the more varied the classes of work that can be 


18 


FOUNDRY PROBLEMS 


successfully performed on them. There is no greater 
mistake than to suppose that one type of machine will 
do all kinds of work. 

The foundry manager, and similarly his superior, 
should make it his business to attend the various 
foundry conventions and exhibits, to study develop¬ 
ments with a view of profiting by them. Again, the 
foremen and superintendents should be sent visiting 
other establishments to see what the trade is doing. 
Reciprocity in this is essential, even if there may be 
a chance of competition, for it is better to be well 
acquainted with your business rival than to be his 
enemy. In a properly balanced factory organization, 
men come home from these inspection tours with full 
value in information for the expenditure, and always 
with the feeling that there is no place like the home 
shop, or better people than the ones who have sent 
them out to see what others are doing. 

Foundry Transportation Facilities.—The study of 
transportation systems in the foundry is another point 
that should be kept constantly in mind by the man¬ 
ager. Are there enough cranes over the molding 
floor? Do tliev interfere with each other, or are they 
overworked? Can you put in a number of jib cranes 
along the side walls or columns to enable a molder 
to close his flasks without waiting until the only 
crane in the shop can come along? Idle men cost 
money. Taking a lot of men away from tlieir jobs to 
test out a mold before closing it finally means break¬ 
ing up their routine to some extent. Hence, improve¬ 
ments in the transportation facilities of a shop should 
always be kept in mind. In the best machine shops. 



FOUNDRY PROBLEMS 


19 


each tool has burden to carry, and strict account is 

kept of performances and percentages of time idle. 

So also in the foundry, although it is not very easy 

to distribute the work so that the appliances are 

always operating. Better here a surplus of apparatus 

than a deficiency. If it is possible to run the railroad 

cars directly into a shop producing heavy castings, 

and if the main crane can also cover part of the yard, 

so much the better. These conditions are not alwavs 

«/ 

possible in an old shop, but can be considered when 
planning to rebuild or move to a new location. 

Cleaning Methods.—When the molds have been 
poured off, the next thing to do is to shake them out. 
Not onlv should molds be allowed to stand awhile so 
that the castings may be black-hot when uncovered, 
but too much of the sand should not be scraped off, 
for that immediately in touch with the molten metal 
has been ruined for further use. The sand has been 
“burnt”, which means that the clay bond of the 
molding sand has been deprived of the chemically 
combined water, and the stickiness of the clay is 
gone forever. Hence this material, injuriously af¬ 
fected to a depth depending upon the thickness of the 
. iron adjoining, should be removed from the floor 
while on the casting, and cleaned off in the cleaning 
department of the foundry. It goes to the dump, and 
is replaced in the sand-heaps by new molding sand. 

Cleaning castings is now done in many ways, de¬ 
pending upon the castings themselves and the facil¬ 
ities of the shop. For medium and small work the 
sand blast is almost obligatory in these days, since 
customers want to see the surfaces of the castings 


20 


FOUNDRY PROBLEMS 


and also to have them free from a skin of burnished 
sand for reasons of economic machining. In quantity 
work with small castings the old tumble barrel will 
probably remain if little or no subsequent machining 
is to be done. Pickling small work also yields results 
for special purposes that is not excelled by other 
methods of cleaning. In the case of large work hand 
labor, supplemented by air operated chisels and 
grinding wheels, covers the situation. 

Whatever process for cleaning is used, the old say¬ 
ing that “prevention is better than cure” applies 
here as well as in the melting processes. If the sand 
walls of the molds are properly prepared by a coating 
of graphite which sticks sufficiently well not to be 
washed away by the stream of molten metal, they 
will not adhere to the casting and eventually come 
away easily, leaving the casting’s surfaces smooth and 
clean. To do this, however, is one of the serious 
problems of the foundry, and a solution has not yet 
been found which can be considered entirely satis¬ 
factory. Hence, the old method of using a specially 
prepared “facing” sand to pack up against the pat¬ 
tern for an inch or more and backing this good sand 
with ordinary sand from the heap, is still in general 
use. The objection to this facing sand lies in the 

fact that it contains a considerable amount of finelv 

•/ 

ground gas coal—called sea-coal—which on contact 
with the molten metal forms a thin layer of gas be¬ 
tween sand and metal for the moment. While the 
result is a smoother surface, particularly if a coat of 
graphite has been put on in addition, the returned 
sand after shaking out has had its bond damaged by 


FOUNDRY PROBLEMS 


21 


the exceedingly fine coal dust, and therefore the sand 
heaps deteriorate. Eventually some method will be 
found to apply graphite to a mold surface so that it 
will stick under all conditions, then the use of sea- 
coal will be a thing of the past. 

Some Points in Core-Making. —While it is axiomatic 
that any intelligent man picked up from the streets 
can be taught core-making quickly, and hence the 
wages paid in the core room today when contrasted 
with those given skilled molders are preposterous, 
nevertheless the guiding head of the core room must 
be well informed. Cores must be made of materials 
compounded to suit the requirements of the casting. 
The fundamental condition is that a core should stand 
up under the stream and pressure of molten metal 
without yielding long enough to allow the metal to 
set, and then be sufficiently destroyed to be easily 
removable. Since metals and alloys contract on cool¬ 
ing, unless a core can yield a little when this final 
contraction takes place, the casting is apt either to 
crack or be so full of casting strains that it is weak 
and really should have the benefit of an anneal. 
Where the metal has been oxidized in the melting, a 
hard core is almost certain to crack a large casting 
which entirely surrounds it, as such damaged metal 
will not stretch in the setting. Hence the advisability 
of holding the clay content of the core sands used to 
a minimum, as these make for a hard core. 

The usual mixture of part old cores, molding sand 
and new core sand free from clay should be watched, 
for the ideal core is made of a rough-grained beach 
sand, free from clay, with just enough core-binder to 


FOUNDRY PROBLEMS 


99 


hold it together properly. Such a core will vent 
splendidly—that is, allow gases to pass through it— 
and be easily removable in the shaking-out process. 
Modern core rooms are equipped with coremaking 
machines, drying ovens with regulation of tempera¬ 
ture conditions, racks on wheels, mixing machinery, 
good benches for the operatives, plenty of light and 
ventilation, and storage facilities. 

Since the binder for cores is usually applied with 
water, the process of “drying” rather than baking a 


core is divided into two stages. The first is the re¬ 
moval of the moisture, which presupposes ventilation 
within the core oven to allow the water vapor to 
escape up the chimney. Second is the ability to raise 
the temperature so that the best working heat be 
given the cores as required by the particular binder 
used. In general it is best to give just a little more 
heat than is necessary for the best strength, as this 
will aid in preventing an absorption of moisture later 
on when the core is set in a green-sand mold, or is 
stored for future use. A good core room foreman 
should be selected, for he should be able to do con¬ 
siderable experimenting with mixtures and binders 
so that he can bring out a line of cores just adapted 
for the requirements of each case and with due re¬ 
gard to plant economy. 

Difficulties Due to Contraction of Metals.—A plant 

manager will do well to remember that there is a % con¬ 
stant warfare—friendly or otherwise—waged between 
the pattern shop and the foundry on the one hand, 
and between the foundry and machine shop on the 
other. This lies in the nature of things. The suppo- 





FOUNDRY PROBLEMS 


23 


sition is that iron contracts after setting at the rate 
ot about an eighth of an inch to the foot. Brass, alu¬ 
minum, and other metals and alloys contract similar- 
ly, but with different figures. Practically, however, 
much depends upon the shape of the casting, the con¬ 
dition of the cores, and other circumstances, so that 
some parts of a casting will be found to have con¬ 
tracted more than others. Popular parlance lias it 
“shrunk” instead of contracted, but a “shrink” is 
the tearing apart of metal inside the casting where 
the last liquid metal remained unable to be replen¬ 
ished through the gate or riser; whereas the “con¬ 
traction” that must be figured on when making a pat¬ 
tern takes place after the casting has set altogether, 
and is the reduction in dimensions from red heat to 
the cold state. 

Now, since the amount of contraction will vary in 
a casting, the foundryman will blame the pattern¬ 
maker when the castings do not measure up correct¬ 
ly, and the patternmaker will claim his work is all 
right. So also with the machine shop where the cast¬ 
ings are wanted soft enough to machine easily. This 
the foundry cannot always give, for to do so would 
require theoretically that each casting have a differ¬ 
ent composition to give the best qualities, and only 
one or two mixtures can be run safely from a cupola, 
and only one from a furnace. 

The differences between pattern shop and foundry 
lend themselves to adjustment as experience piles 
up. The ordinary custom where a number of castings 
from the same pattern are to be made is to mold up 
and pour one, measure it up carefully, and then 


24 


FOUNDRY PROBLEMS 


change the pattern to give the correct final results. 
In the case of foundry versus machine shop, however, 
the adjustment of trouble requires a lot of tact, for 
the foundry man really has much to contend with. In 
making the mixture attention is given to the demands 
of the lighter sections of the castings to be made. 
The aim is to get these soft enough to machine with¬ 
out too much difficulty. The heavier sections will 
then surely be soft enough. Unfortunately, however, 
these heavier sections will be weaker than may be 
wanted, and hence a harder iron will have to be made 
in spite of the machining qualities involved. Herein 
lies the difference between American and European 
practice. In the former machinability is demanded 
above almost everything else, for the factors of safety 
used are large. In Europe, however, they have to 
deal with closer cost margins, and hence a casting is 
made to serve its purpose whether machining is diffi¬ 
cult or not. In the larger foundries of America this 
question is generally handled by leaving the deter¬ 
mination of the mixtures to the care of the metal¬ 
lurgist who has to find the dividing line between 
service and machinability. Unless the metallurgist is 
a man of ability and tact, he has an excellent oppor¬ 
tunity of being in hot water with both foundry and 
machine shop. 

Keeping Watch on Costs. —In the course of the 
various foundry operations it is necessary that costs 
be watched closely. A complete system of forms for 
getting productive and non-productive labor costs; 
forms for following up the patterns and shop orders 
for castings to be made, material requisitions, and 


FOUNDRY PROBLEMS 


25 


any number of data may be wanted to give the cor¬ 
rect answer to any question connected with the pro¬ 
duction end. There is danger in multiplying this too 
greatly just as much as allowing leaks to pass unob¬ 
served. There must be a practical reason for every 
bit of information wanted day in and dav out, other- 
wise the foundry office will become top heavy with 
clerical help. When boiled down to departmental 
costs per hundred pounds, with overhead clearly indi¬ 
cated, and so on, the manager can have his fingers on 
the pulse of the establishment constantly, and while 
knowing exactly what is going on, prepare for what 
his vision should tell him is ahead. 

Observation of Manufacturing Tendencies. — This 
brings the subject to the point of judging what is 
ahead. Men of affairs in any industry connect them¬ 
selves not only with their respective representative 
bodies, but also with local and further reaching 
bodies of financial men, so that they mav learn the 
trend of money, commodity production, the disposi¬ 
tion of labor, transportation service and a thousand 
other things that affect business life. These things 
cannot be learned in the establishment itself. The 
salesmen bring in reports of coming conditions and 
movements, and the ear must be kept to the ground. 
In the shop itself, however, there should be the means 
of knowing ahead what lines of operation the indus¬ 
try is tending toward. Visits of the superintendents 
and foremen should disclose this. Each man should 
give much of his spare time for private study of 
books and journals so that he can tell the manager 
what he sees coming rather than be told it. The 



26 


FOUNDRY PROBLEMS 


laboratory is one of the best places for exchange of 
thought between the technical staff and the men who 
guide operations. Our large industrial establishments 
recognize this, and either instruct the foremen to 
drop in at the laboratory now and then or else every¬ 
one of importance lunches at the same time and place. 

A good plan is to have the numerous journals that 
sift into a plant by subscription or oilier wise directed 
first to the laboratory. The metallurgist should then 
skim over the content, digest and mark pertinent 
articles, and pass them on to those most interested. 
Reports should be sent as memoranda to the manager 
for his files, so that he may know the gist of an article 
or be able to call for it. In time, a respectable library 
is thus accumulated which becomes invaluable in plan¬ 
ning changes or otherwise increasing the efficiency of 
the establishment. Our modern works seldom look as 
they did a decade ago apart from the expansion side. 
Methods change, the public taste or requirements 
change, and the manufacturing plant that does not ad¬ 
just itself to the times eventually lias to leave the 
field. Fortunately plant changes are not made over¬ 
night, and the purchasers of the product have eventu¬ 
ally to pay for these changes. 

Keeping the Plant Up-to-Date.—Probably the best 
way to handle the general plant situation—unless new 
discoveries or exceptional circumstances require it 
otherwise—is to do as wise township officers handle 
the road problem. Instead of patching up indiscrimi¬ 
nately and having a road system always on the point 
of breaking down, a considerable portion of the avail¬ 
able funds is spent at one or more points as part of a 




FOUNDRY PROBLEMS 


27 


first-class permanent way. The balance of the money 
is spent in upkeep for the rest of the roads. So also 
in a foundry: An appropriation should be made every 
year for the thorough reorganization of a single de¬ 
partment—from the ground up. For instance, a new 
core room is built, in every respect up to date and of 
ample capacity for years to come. The rest of the 
plant is kept in the shape that is required. As, year 
by year, a plant is thus improved in its several de¬ 
partments, it cannot help but be fairly up-to-date all 
the time. Advantage will naturally be taken of the 
times. Building when everything is high is out of 
question, but during times of industrial depression is 
just the time to get ready for the following expansion 
which is certain to come. Pig iron can be contracted 
for similarly, and the yard can be stocked up heavily. 
When the rush comes, the material is at hand to pro¬ 
duce promptly and with good raw materials—a thing 
which is not possible when no provision has been 
made and resumption comes on unexpectedly. 

The foundry is a place in which an endless variety 
of things happen. The forces of nature are made to 
yield in many ways. Safety must be watched for in¬ 
stinctively by every one at work. There is danger 
everywhere. The reward is not large but it is satis¬ 
factory, and there is a consciousness that not every 
one can win out against the refractory character of 
the inanimate things encountered. All the more the 
satisfaction of those who do. The high points only 
have been touched in what has been given, but it is 
the hope of the writer that the view shown of a won¬ 
derful industry has been of some value. 






































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